Flexible tool



Dec. 10, 1935.

L. B. MILLER 2,023,693

FLEXIBLE TOOL Filed April 3, 1935 INVENTOR.

Leo/z B/Yiller BY ATTORNEY.

Patented Dec. 10, 1935 PATENT OFFICE I FLEXIBLE- 'roon Leon B. Miller,New York, N -Y.

Applicationliprll 3, 1935, Serial No. 14,454

4 Claims.

- This invention relates to flexible tools similar to those described inmy co-pending application, Serial No. 758,455, filed December 20th,1934.

The prime object of this invention is to provide a tool, such as a screwdriver, socket wrench,

drill, reamer, or the like, with a flexible connection between thehandle end and the work-engaging end which permits the operation of thelatter end while the handle end is disposed either in alignment withsaid work-engaging end or at any desired angle thereto.

Another object of this invention is to so construct the flexibleconnection between the ends of the tool as to not only permit theworking of the device while being flexed, but which will resist anytorsional action in either bent or straight position, and which will,when not in use, assume its normal straight-line position between thetool ends.

Another. object of this invention is to provide within a tool aconnector consisting of more than two nested or laminated layers ofclosely and steeply wound coils in which the direction of winding of onecoil is opposite to the direction of the next adjacent coil, and inwhich the material from which the coils are wound increases in size fromwithin to without.

With the foregoing. and still further objects in view, this inventionwill be more clearly understood from the following description, inconjunction with the accompanying drawing, forming part of mydisclosure, but which drawing is not intended to limit my invention tothe actual showing.

In the drawing, Figure 1 illustrates a typical construction of a screwdriver, partly in section, and equipped with a flexible connectorbetween the handle end and the work-engaging end of the tool.

Figure 2 illustrates an enlarged cross-section through one form of myflexible connector, such as may be taken on lines 2-2 of Figure 1.

Figure 3 illustrates a similar cross-section through a connector of adifferent construction.

Figure 4 illustrates a screw driver bit of a modified form from thatshown in Figure 1.

Figure 5 illustrates a socket wrench attachable to the connector.

Figure 6 illustrates an adapter, which may be used instead of a screwdriver bit and may be attached in the same manner to the flexibleconnector, and

Figure '7 shows a modified construction of a flexible screw driverpreparatory to its assembly.

Referring now to the figures, numeral H) denotes the handle end of mydevice, such as used in screw drivers or similar tools and which ispreferably equipped at H with a ratchet arrangement to permit itsoperation in either a righthand or left-hand direction, or to prevent itfrom 5 moving in either direction. Below'the ratchet arrangement, thereis provided a receiving socket l2, into which is passed the upper end ofmy flexible connector and which is brazed or soldered within the socket,as indicated at l3. At the 10 lower end of the connector, there will beobserved the work-engaging end of my tool, also illustrating a socketmember I4, in which the connector end is soldered or brazed in at I5.The workengaging end in Figure 1 consists of a screw 15 driver bit It,extending from an enlargement l1, above which is located a cup I8 withthe knurled outer surface, and the lower end of which l9 engages asuitable groove 20. .Cup l8 serves for holding the screw driver end inposition with 20 reference to the work when the latter engages a screwor bolt, while handle end l0 may be operated from any desired direction.

The flexible connector consists of an innermost coil 2|, formed bywinding two relatively thin, 25 resilient, steel wires at a certainpitch in one direction. Surrounding innermost coil 2| and in intimatecontact therewith is the next coil 22, made from three somewhat heavier,resilient, steel wires, and wound in opposite direction to 3 the windingof coil 2|.

Surrounding'coil 22 is a third coil 23, consisting of four resilientwires of heavier gage than those employed in coil 22, and wound inopposite direction to the windings of the latter coil. 35

Finally, there is an outer helix 24 of .still heavier gage, surroundingcoil 23 and consisting of four wires wound in opposite direction to thewires of coil 23. The arrangement of the coils and the number of wiresemployed in each of the 40 coils may be clearly seen from Figure 2, anda similar arrangement of a flexible connector is shown in cross-sectionin Figure 3, where instead of four laminations of coils, six laminationsare employed, and where the inner coil consists of 45 two wires, thenext adjacent of three wires, the third of four wires, the fourth offour wires, the fifth of five wires, and the outer coil of seven wires.Both illustrations (Figures 2 and 3) are shown without a mandrel, but itis obvious that in order to facilitate the winding of the innermost coiland for the purpose of giving the connector more rigidity, a wiremandrel may be placed into the center of the connector.

The purpose of constructing the flexible con- 6.

V with a collar or thimble nector in the manner stated above becomesquite obvious when it is considered that the tool may be twisted ineither a right-hand or left-hand direction and must transfer suchmovements from the handle tothe screw driver bit without any lost motionand without destruction to the connector. For this reason, the coilsnested within one another are wound in opposite, directionsto oneanother so that when the strain is in one direction, tending tounwindone of the coils, the next adjacent coil will counteract suchforce since it will be, so to speak, woundtighter, thereby preventingthe unwinding of the first mentioned coil. It is to bepconsidered thatthe ends of the connector are immovably set within the sockets of thehandle end and work-engaging end so that the ends of all coils are fusedtogether, which fact prevents unwinding or otherwise dismembering of theindividual coils. It will be also noted that in order to provide therequired flexibility of the connecting member, the innermost coil ismade of relatively thin wires, and only two wirers are employed to formthe coil. Therefore, the pitch of the innermost coil 4 is considerablyless than the pitch of the outermost coil, which is made of heavier wireand in which four wires are used. The gradual increase in thickness fromwithin to without and the employment of a smaller number of wires in theinner coils and a larger number of wires at the outer coils, andtherefore the increased pitch of the coils'from within to without, alltends to supply the necessary flexibility and the torsional resistanceof the connector.

In Figure 1, the'work-engaging end is provided It, by means of which thetool end may be held in proper position relative to the work which itengages, but such provision is not absolutely required, as shown inFigure 4, where a screw driver tool end 25 is illustrated, provided witha socket or depression 29, adapted to accommodate the lower end of theflexible connector.

Another work-engaging end is shown in Figure 5 in the form of a socketmem'ber'il, also provided with a connector engaging end 29.

Still another work-engaging member is shown in Figure 6 consisting of asocket end 29, provided with a connector engaging end 99. The socket endis preferably equipped with a set screw 3|, passing through an annularenlargement 92, which set screw is adapted to engage a tool, such as 'adrill. screw driver bit, reamer or socket wrench, which may be insertedinto socket mem- 1 vention, particularly including various modiflca- 55bgr 29, and immovably held therein.

Figure '7 illustrates a modified construction of my screw driver in itsdis-assembled state, showing each of its constituent parts preparatoryto being set together. There is-again shown a handle member 39,terminating in ahollow socket 94, which latter is adapted to receive theupper end of a flexible connector 35. It will be observed that thisconnector is provided with a. mandrel 36, which is permitted to remainwithin the central coil of this connector.

Beneath the lower end of the connector, there is shown a modifiedassembly of a work-engaging construction which consists of aconneotorreceiving member 31, provided with a socket for accommodating the lowerend of the connector. The lower portion of member 31 is shapedconically, as indicated at 39, and terminates in another hollow socketportion 99.. This socket is adapted in receive the upper end 49 of ascrew driver bit In engagement with the conical surface 99 'and with thetop surface of socket member 81,

is an outer, preferably knurled ferrule 42, adapted to freely rotaterelative to the socket member. It serves the same purpose as ferrule II,de- 5 scribed in connection with Figure 1.

In the modification of Figure '1, it will be observed that sockets 34and 31 are relatively narrow and correspond with their inner diametersto the outer diameter of the connecting mem- 10 her 35. Thisconstruction is intended to provide a different connection betweensocket extensions 34 and 31 and the flexible connector 35, in that thesesocket portions are intended to be shrunkonover the flexible connector.

The attachment of screw driver bit 4 I, by means of its extension 40,within socket I9 is preferably made by compressing the body of socket 39against the flat surfaces'of extension 49, al-

though any other manner of attachment may be employed.

In the foregoing description, I am speaking 'of -flexible connectorsconsisting of more than two laminae of coils, in which two adjacentcoils are wound in opposite direction to one another. Coils made ofrelatively heavy gage wire, such as shown in Figure 2, do not requirethat the mandrel, employed for forming the innermost coil, be retainedwithin that coil, whereas, connectors made of. relatively light gagewire coils preferably retain the mandrel within the innermost coil. Insuch event, the mandrel has a tendency of straightening out theconnector, after release from a bent position, to assume its normal,straight position.

I have found during experiments conducted 85 with the construction ofdifferent connectors, that at least three internested coils must beemploycd in order to produce the desired effects of flexibility andresistance to torsion. However, the most advantageous effects wereachieved by employing connectorsmade of double coils, or multiplesthereof, in which each double coil, one of the coils is wound in onedirection while the other coil is wound in the opposite direction. Thus,I preferably employ either four, six, eight, or ten coils, etc., and themore coils I use, the greater number of wires I employ for each coil.Obviously, the number of wires change the pitches of the coils, and I soform my connectors that the innermost coils of less number of wires arealso of lesser gage, andas I buildup the coils from within to without,both the sizes and numbers of the wires are increased.

While I have shown specific forms of my intions of the connector, asshown in Figures 1, 2, 3 and '7, with or without a mandrel at theircenter, and while I have'shown such flexible connectors to be ofundetermined length and diameter, it is self-understood that suchconnectors may be made of any length or any diameter as may be requiredfor the purposes for which the tool is employed, and that the variousdetails of constructions illustrated may be changed and improved, aswell as the manner of intercon- 55 necting the different parts, and Itherefore reserve for myself the right to make changes and improvementsin my invention, without departing from the broad scope thereof, as setforth in the annexed claims.

I claim:

1. In a flexible tool, handle and work-engaging members, a flexibleelement connecting them and consisting of a plurality of laminated coilsof multiple, resilient wires, increasing in wire crosssection, number ofwires and coil pitch from within to without, and alternating as to thedirection of windings, all coil termini at both ends of said elementbeing fused together for preventing their unravelling, said handle andwork-engaging members provided with means for accommodating the fusedends of said element, and means for securely holding the element endswithin said accommodating means.

2. In a flexible tool, as set forth in claim 1, said work-engagingmember provided with means for directing, and for holding said member inengagement with the work, while the tool is being operated.

3. A flexible screw driver, comprising in combination, a handle member,a screw driver bit member, both members provided with sockets, aflexible connector immovably held at its ends within said sockets andconsisting of at least four internested coils made of multiple,resilient wires, each coil having a uniform, substantially cylindricalshape throughout its entire length, the coils increasing in wire size,wire numbers and pitch from within to without, and being woundalternately in opposite directions, all coil termini at both ends ofsaid flexible connector, held within said sockets, being fused togetherfor preventing the unravelling of the coils.

4. In a flexible screw driver, a handle member, provided with aconnector-receiving socket, a work-engaging mechanism provided with afreely operative collar, a connector-receiving socket, bit-engagingmeans and a bit secured within the latter, a flexible connector fixedlysecured with its ends against movement within the connectorreceivingsockets of said handle member and said mechanism, said connectorcomprising a plurality of coil laminae, alternating as to the directionsof their windings, each coil consisting of a plu- 15 rality of wires,the cross-section of the wires, their number and the pitch of the coilsincreasing from within to without, said coils being substantiallycylindrical in shape over their entire length,

the termini of all coils at both ends of said con- 20 nector being fusedtogether for preventing them from unravelling.

LEON B. MILLER,

